First United Arab Emirates Conference on Pure & Applied Chemistry (ECPAC11)

Hikmat S. Hilal's picture
Research Title: 
Surface Treatment of Novel SEmiconducting Materials: Utilization in Renewable Energy and Water Purification
United Arab Emirates
Thu, 2001-03-01
Research Abstract: 
emiconductors (SC) are a very important area of advanced materials. Almost all contemporary technologies rely on SC systems such as p-n junctions (transistors, diodes, PV, PEC, refregiration, ….). Semiconductor research activity has been established in these laboratories in the mid 1990s. The activity started with modification of mono-crystalline n-Si and n-GaAs semiconductor surfaces for the purpose of controlling band edge positions. This was to tailor band edge positions to catalyze water splitting (into hydrogen and oxygen) by solar light. The objectives were successfully achieved by graduate students here. To simultaneously achieve stability and efficiency of the SC electrode, newer techniques were developed. Monocrystalline n-GaAs electrodes were successfully enhanced (in both stability and efficiency, and band edge control) using polymeric coatings with electroactroactive ions inside. However, with increasing cost of monocrystalline SC materials, our objectives have changed. Our efforts were then diverted to synthetic thin film SC electrodes. Preparation of enhanced semiconducting materials, in the forms of thin films and nano-scale particles, have then been conducted for the purposes of light-to-electricity and for water decontamination strategies.Recently, students have been heavily engaged in preparing new classes of n-type semiconducting materials (CdS and CdSe) in the forms of thin films and nano-scale particles using Chemical Bath Deposition (CBD) and Electro-Chemical Deposition (ECD) techniques. CdS and CdSe nano-films were deposited onto FTO/glass systems and are currently being used for light-to-electricity conversion processes. Modification of thin films with different techniques shows promising potential in enhancing both efficiency and stability. For the first time, CBD-based CdSe films were stabilized and effectively used in PEC processes. Our future strategies in enhancing SC electrodes, using surface modification, will be highlighted. In addition to the abovementioned applications, removal of microorganisms has also been studied using PEC systems. Application of PEC systems in cancer treatment will also be examined in the next couple of years. Prospects of future cooperation between these laboratories and others will also be discussed.